open access

Vol 52, No 4 (2014)
Original paper
Submitted: 2014-12-05
Accepted: 2014-12-18
Published online: 2014-12-19
Get Citation

Interrupted orthodontic force results in less root resorption than continuous force in human premolars as measured by microcomputed tomography

Monika Sawicka, Rossella Bedini, Piotr M. Wierzbicki, Cornelis H. Pameijer
DOI: 10.5603/FHC.a2014.0037
·
Pubmed: 25530465
·
Folia Histochem Cytobiol 2014;52(4):289-296.

open access

Vol 52, No 4 (2014)
ORIGINAL PAPERS
Submitted: 2014-12-05
Accepted: 2014-12-18
Published online: 2014-12-19

Abstract

Introduction. Root resorption is an undesirable but very frequently occurring sequel of orthodontic treatment. The aim of this study was to compare root resorption caused by either continuous (CF) or interrupted (IF) orthodontic force.

Material and methods. The study was performed on human subjects on 30 first upper and lower premolars scheduled for extraction for orthodontic reasons. During four weeks before extraction 12 teeth were subjected to either CF or IF. The force was generated by a segmental titanium-molybdenum alloy cantilever spring that was activated in buccal direction. Initially a force of 60 CentiNewton was used in both CF and IF groups, the force in the former, however, was reactivated every week for 4 weeks. There was no reactivation of force in the IF group after initial application. A morphometric analysis of root resorption was performed by microcomputed tomography and the extent of tooth movement was measured on stone casts. Furthermore, a Tartarate-Resistant Acidic Phosphatase activity (TRAP), the marker enzyme of osteoclasts and cementoclasts, was determined by histochemical method. The Mann-Whitney U test was used to compare the difference in measured parameters between treatment and control tooth groups.

Results. The number of resorption craters was significantly higher and their average volume almost twice as large in the CF compared to the IF group (p < 0.05). However, the distance of tooth displacement was similar for both groups. Cementoclasts were detected with the TRAP technique on the surface of two teeth only; both were subjected to continuous force.

Conclusions. The use of IF leads to less destruction of root structure as opposed to continuous force while the same tooth movement was achieved.

Abstract

Introduction. Root resorption is an undesirable but very frequently occurring sequel of orthodontic treatment. The aim of this study was to compare root resorption caused by either continuous (CF) or interrupted (IF) orthodontic force.

Material and methods. The study was performed on human subjects on 30 first upper and lower premolars scheduled for extraction for orthodontic reasons. During four weeks before extraction 12 teeth were subjected to either CF or IF. The force was generated by a segmental titanium-molybdenum alloy cantilever spring that was activated in buccal direction. Initially a force of 60 CentiNewton was used in both CF and IF groups, the force in the former, however, was reactivated every week for 4 weeks. There was no reactivation of force in the IF group after initial application. A morphometric analysis of root resorption was performed by microcomputed tomography and the extent of tooth movement was measured on stone casts. Furthermore, a Tartarate-Resistant Acidic Phosphatase activity (TRAP), the marker enzyme of osteoclasts and cementoclasts, was determined by histochemical method. The Mann-Whitney U test was used to compare the difference in measured parameters between treatment and control tooth groups.

Results. The number of resorption craters was significantly higher and their average volume almost twice as large in the CF compared to the IF group (p < 0.05). However, the distance of tooth displacement was similar for both groups. Cementoclasts were detected with the TRAP technique on the surface of two teeth only; both were subjected to continuous force.

Conclusions. The use of IF leads to less destruction of root structure as opposed to continuous force while the same tooth movement was achieved.

Get Citation

Keywords

human premolars; root resorption; continuous and interrupted orthodontic force; microcomputed tomography; TRAP; cementoclasts; reparative cementum

About this article
Title

Interrupted orthodontic force results in less root resorption than continuous force in human premolars as measured by microcomputed tomography

Journal

Folia Histochemica et Cytobiologica

Issue

Vol 52, No 4 (2014)

Article type

Original paper

Pages

289-296

Published online

2014-12-19

DOI

10.5603/FHC.a2014.0037

Pubmed

25530465

Bibliographic record

Folia Histochem Cytobiol 2014;52(4):289-296.

Keywords

human premolars
root resorption
continuous and interrupted orthodontic force
microcomputed tomography
TRAP
cementoclasts
reparative cementum

Authors

Monika Sawicka
Rossella Bedini
Piotr M. Wierzbicki
Cornelis H. Pameijer

Regulations

Important: This website uses cookies. More >>

The cookies allow us to identify your computer and find out details about your last visit. They remembering whether you've visited the site before, so that you remain logged in - or to help us work out how many new website visitors we get each month. Most internet browsers accept cookies automatically, but you can change the settings of your browser to erase cookies or prevent automatic acceptance if you prefer.

By "Via Medica sp. z o.o." sp.k., ul. Świętokrzyska 73, 80–180 Gdańsk

tel.:+48 58 320 94 94, faks:+48 58 320 94 60, e-mail:  viamedica@viamedica.pl